Experimental Investigation of Shock-Wave–Streamwise-Vortex Interaction

Wind tunnel experiments were conducted at incoming Mach numbers (Formula: see text) of 2.01 and 2.81 to investigate the interactions between shock waves and weak, moderate, and strong streamwise vortices in a concave channel representing the inward-turning inlet/isolator flow of hypersonic engines. Synchronized high-speed schlieren visualizations and high-frequency wall static pressure measurements were collected to evaluate the steady-state and dynamic characteristics of the global and local flowfields. The interference of streamwise vortices bifurcated the oblique shock wave; the stronger the former, the more severe the deformation of the latter with increasing intensity during downstream development. When Formula: see text, moderate and strong streamwise vortices caused the Mach stem in the shock train leading edge (STLE) to bend upstream; when Formula: see text, moderate and strong streamwise vortices caused the top- or bottom-wall shock waves in the STLE to bend and bifurcate into multiple shock waves. An increase in streamwise vortex intensity weakened the self-excited oscillations of the shock train and enhanced the pressure fluctuations caused by STLE oscillations. The dominant frequency of the interacting flowfield oscillation was 20–40 Hz, and the dominant wave structure in the shock train oscillated rigidly. These results can inform hypersonic engine inlet development.